Internal combustion engines are efficient ways of creating power in movable and fixed applications. Examples of the former include vehicles such as trucks, tractors and boats. Examples of the latter include generators, pumps, welders and the like.
A substantial after-market has developed for repair and rebuilding of these engines, with normal wear on removable parts like liners, piston rings, and bearings. These parts have to be periodically replaced in order to maintain the service life of individual engines.
With newly formulated low emission fuels, increasing compression ratios, boost pressures, operating temperatures, exhaust gas recirculation, speeds and other parameters, an efficient way of providing cooling for the parts associated with combustion is becoming more important, particularly at the critical location near the top of the cylinder liner surrounding the combustion chamber at the firing zone.
There have been many attempts to provide such cooling in engines. Examples include: 1) the shunt flow cooling system utilized in the Detroit Diesel Corporation internal combustion engines; 2) the ring flange cooling system utilized in Mercedes engines; and, 3) the lubrication oil cooling circuit used by Cummins Engine Company. A Detroit diesel engine is set forth in U.S. Pat. No. 5,299,538 while examples of the latter two are set forth in U.S. Pat. Nos. 3,363,608 and 4,413,597, respectively.
The cylinder liners now sold for use with these types of engines are typically made of chilled cast iron with a thorough hardness on the range of 45-47 Rockwell C. This hardness, while providing a hard running surface for a piston utilized with the liner, renders the liner stiff and non-compliant. It also requires grinding or honing for any post-hardening manufacturing procedures.